The present invention provides a force sensor correcting method which is simple and capable of performing correction, with the force sensor remaining mounted at the end of an arm without an exchange of an end effector. In the present invention, a force sensor 1 of one robot 101 has already been corrected, and a force sensor 2 of the other robot 102 is an object to be corrected. First, hands 3a, 3b of a pair of robots 101, 102 are made to abut on each other (abutting step). A detected signal of the corrected force sensor 1 of the one robot 101, generated by execution of the abutting step, is converted into a measured value indicating a force or a moment (measurement step). Based on the measured value obtained in the measurement step, a value indicating a force or a moment acting on the hand 3b of the other robot 102 due to a reaction generated by the abutting step is obtained (calculation step). The conversion data is updated such that a detected signal, outputted by the force sensor 2 as the object to be corrected of the other robot 102 in the abutting step, is converted into an identical value to the value indicating the force or the moment obtained in the calculation step (correction step).